1No Voltage Drop: Automatically combines two batteries when charging and isolates the two batteries when not charging. No voltage drops comparing to battery isolator diodes. 2Lower Power Consumption: Optional storage mode allows zero power consumption when engine is off. 3Voltage Sensitive Relay: Dual battery isolator ensure your primary battery is always charged and ready to start your vehicle. It's like having two separate power sources for each battery while only having one alternator. 4Stable Performance: This dual battery isolator is also built to withstand extreme weather environments, vibration and waterproof. 5Easy Installation: No alternator or ignition connection needed,You don't need any additional components to complete installation as everything is included in the kit, including leads, connectors, screws, and more.